Heretofore, for this type of removal and installation device, there are the one for a shaft mode which can install or remove an external snap ring in/from a key groove on a shaft with separated both ends and the one for a hole mode which can install or remove an internal snap ring in/from a key groove of a hole with both ends brought close and they are dedicated removal and installation devices.
Concretely, in a removal and installation device used when an external snap ring is removed or installed, symmetrical levers continuously formed in a shape except projected working tools on the sides of the ends and gripping levers on the sides of bases support respective curved parts and are coupled to the curved parts so that both projected working tools are parallel, the projected working tools at both ends are bent in a direction in which they are separated, are inserted into holes at both ends of the snap ring when the removal and installation device is used, and when gripping levers are gripped and both ends of the snap ring are widened by both projected working tools, the locking of the holes of the snap ring and the projected working tools is kept and the external snap ring can be securely removed or installed from/in a key groove on a shaft.
Besides, in a removal and installation device used when an internal snap ring is removed or installed, a pair of right and left side levers provided with projected working tools on the sides of the ends and gripping levers on the sides of bases are crossed in an X shape, the crossed parts are supported, the projected working tools at both ends are curved in directions in which they approach, are inserted into holes at both ends of the snap ring when the removal and installation device is used, when the gripping levers are gripped and both ends of the snap ring are brought close by both projected working tools, the locking of the holes of the snap ring and the projected working tools is kept and the internal snap ring can be securely removed or installed from/in a key groove of a hole.
However, these removal and installation devices have a problem that they cannot be used for both the external snap ring and the internal snap ring.
To solve such a problem, these applicants proposed a removal and installation device in which switching to an external snap ring and an internal snap ring was enabled by one operation (refer to Japanese published unexamined patent application No. Hei10-264051).
The removal and installation device is configured so that right and left rotary shafts and a movable pin are interlocked by turning right and left beaks, projected working tools can be set to a hole mode when they are directed inside and in the meantime, when the projected working tools are directed outside, they can be set to a shaft mode.
Though remarkable effect that the removal and installation device in the above-mentioned proposition by these applicants can be switched and set to a hole mode in which the internal snap ring can be removed or installed or a shaft mode in which the external snap ring can be removed or installed is produced, work for turning the right and left beaks is required, a mechanism for interlocking the right and left rotary shafts and the movable pin by turning the right and left beaks is required to be provided in an operating lever provided at the end of a gripping lever and the removal and installation device has a problem that the structure is complex.
The invention is made in view of the above-mentioned conventional situation and the object is to provide a new removal and installation device for external and internal snap rings based upon a removal and installation device that can be switched to a shaft mode in which right and left projected working tools are operated in directions where they are separated when right and left gripping levers are gripped or a hole mode in which contrary to this, both projected working tools are operated in directions where they approach and characterized in that no troublesome work such as turning right and left beaks is required, the new removal and installation device can be switched to the shaft mode or the hole mode by extremely simple operation and more excellent effect is produced in controllability, workability, serviceability and easiness in handling.